1. Technical Field
The present invention relates to an electric power tool such as an impact driver including a vibration mechanism that provides vibration in an axial direction to a final output shaft protruded forward from a housing.
2. Description of the Related Art
An electric power tool with a vibration mechanism includes a final output shaft, such as a spindle or an anvil, that protrudes forward of a housing accommodating a motor and such that rotation is transmitted from the motor, the housing including a vibration mechanism that provides vibration in the axial direction to the final output shaft. For example, Japanese Patent No. 4468786 discloses, as the electric power tool with a vibration mechanism, an impact driver that includes a vibration mechanism including a first cam secured integrally to an anvil as a final output shaft, a second cam that interlocks with the rear of the first cam and is fitted to the exterior of the anvil to be rotatable, and a vibration switching lever (vibration switching member) having, at the front end, a locking tooth capable of meshing with a locking tooth formed on the outer circumference of the second cam. In the impact driver, a connecting protrusion provided to the vibration switching lever is loosely inserted in a vibration switching groove provided to a switch case. By rotating the switch case using a switch button, the vibration switching lever is moved forward or backward to the forward position in which the vibration switching lever meshes with the second cam or the backward position in which the vibration switching lever is apart from the second cam. This enables switching of the vibration on and off.
However, in the conventional electric power tool with a vibration mechanism, the second cam and the vibration switching member are arranged in series in the axial direction, and the locking tooth provided to the front end of the vibration switching member is meshed with the locking tooth on the outer circumference of the second cam. Accordingly, the dimension of the vibration switching member in the axial direction is long and the space occupied by the entire vibration mechanism is large. As a result, it prevents downsizing of the entire tool.